1. Field of the Invention
The present invention relates to a flat display such as a liquid crystal display device or organic electronic-luminescence display device e.g., and more particularly, to the structure of a flat panel display device including a supporting member for mounting a liquid crystal panel on various devices.
2. Description of the Related Art
In general, when a flat panel display device such as liquid crystal panel is attached to an electronic device such as portable phone or personal computer, a supporting member made of a synthetic resin is employed to support the liquid crystal panel. The supporting member includes an engaging element via which the supporting member is attached to a circuit board or the like disposed in the electronic device. Various types of engaging elements are known. They include a screw hole via which the supporting member is fastened to the circuit board with a screw, a hook-shaped element designed to be inserted into a fixing hole formed in the circuit board such that the hook-shaped element engages the fixing hole, etc.
Some supporting members include a backlight or at least a part, such as a light guiding member for guiding light from light source toward liquid crystal panel, of the backlight disposed behind the liquid crystal panel. Sometimes the backlight or the part of the backlight is formed integrally with the supporting member. In this case, the supporting member is formed by means of molding using a transparent resin such as acrylic resin, polycarbonate resin, etc. In this case, a light emitting element such as an LED serving as a light source of the backlight is generally mounted on a circuit board of an electronic device such that the light emitting element is located at the side of an end of the light guiding member of the supporting member mounted on the circuit board thereby allowing light emitted from the light emitting element to be introduced into (incident on) the light guiding member via its end. In some cases, the light emitting element is mounted on the supporting member.
When the liquid crystal panel is attached to the circuit board or the like via the supporting member as described above, electrical connection between the liquid panel and the circuit board of the electronic device is achieved by means of inserting or fitting (engaging) an interconnection terminal part, which is formed on an end portion of a flexible interconnection board electrically connected to the liquid crystal panel, into a connector mounted on the circuit board or by means of soldering. In this case, when the liquid crystal panel is mounted on the circuit board, the liquid crystal panel is first supported by the supporting member, and then the supporting member is firmly attached to the circuit board. After that, the connection terminal part formed on the end portion of the flexible interconnection board electrically connected in advance to the liquid crystal panel is connected to the connector. In the case where connection is made by means of soldering, soldering is performed after positioning the end portion of the flexible interconnection board relative to the terminal part on the circuit board.
Various types of connectors are known for use as the connector mounted on the circuit board. They include a connector having an opening slit into which the connection terminals of the flexible interconnection board is inserted, a connector designed to receive the connection terminals of the flexible interconnection board such that the connection terminals engages the connector in a fastener-like fashion, a connector including a movable part capable of being opened and closed wherein, to make a connection, the connection terminal part is placed on the pin terminals of the connector and then the movable part is closed thereby catching the connection terminal part from both sides, etc.
However, the conventional techniques have the following problems. When the conventional flat display panel such as liquid crystal panel is attached to an electronic device, it is required to separately perform the attachment (assembling) of the supporting member and the electrical connection of the liquid crystal panel. Another disadvantage is that a complicated operation is required to solder a flexible interconnection board and a circuit board, or to connect the connection terminals of the flexible interconnection board connected to the liquid crystal panel to the connector of a circuit board. Therefore, the attaching (assembling) operation has to be performed manually step by step. Thus, it is very difficult to mount the liquid crystal panel on an electronic device by means of automation.
Thus, a general object of the present invention is to solve the above problems. More specifically, it is an object of the present invention to provide a structure of a flat panel display such as a liquid crystal display device which allows a display panel supported by a supporting member to be easily attached to a device by means of automation.
According to an aspect of the present invention, to achieve the above object, a supporting member is arranged behind a display panel which has a flat shape. The flat shaped panel such as a liquid crystal panel is employed as a display panel, and a backlight which has a light guiding member is sometimes used as the supporting member. Behind the supporting member, another member such as a circuit board is positioned so as to hold the supporting member between the display panel and the circuit board. The other member is attached to an attaching surface of the supporting member, which is a surface of an opposite the side where the liquid crystal panel is supported.
Between the supporting member and the other member (such as circuit board), a connector which has an elastic characteristic is sandwiched therebetween. Owing to the elasticity of the connector, a contacting conductor pressure toward the circuit board is provided. This ensures that the connector and the other member are electrically connected to each other in a highly reliable fashion. Furthermore, a greater tolerance is allowed associated with the attaching error of the supporting member, and thus the reliability of the electric connection is improved. To obtain an elastic connector, a rubber connector or a connector including an elastic strip formed in a torsion spring structure is employed. By employing a torsion spring structure, it is ensured that high-reliability electric connection is achieved at low cost.
Between the connector and the support member, one end portion of an interconnection member is secured, and an another end of the interconnection member is connected to the display panel so that the other member and the display panel are electrically connected to each other via the connector. To obtain an electrical connection of the circuit board and the interconnection member, terminals may be formed on a surface of the interconnection member, and other terminals may be formed on the circuit board. The terminals of an interconnection member and these of the circuit board face each other via the connector. By employing the interconnection member, it is possible to arbitrarily design the location of the connector and the supporting member regardless of the structure of the liquid crystal panel.
To achieve the electrical connection between plurality of electrodes (connection terminals) on the circuit board and the interconnection member, (although it is possible to use a torsion spring structure), a rubber connector is provided. The rubber connector comprises an insulating elastic material and a plurality of conductive members disposed in the insulating material is preferably used. Alternatively the rubber connector comprises an insulating elastic material and a plurality of metal wires rounded the insulating material.
With this connector, ones of the terminals (interconnection terminals) of the interconnection member and respective ones of the terminals of the circuit board are connected by a respective conductive member. Pressure is applied to the insulating elastic material into contact with the other member thereby achieving electric connection between the connector and the other member. This feature allows a reduction in failures such as short circuits and poor electric connection during the production process. Furthermore, it is possible to obtain the elastic characteristic in the contacting direction without causing an increasing in the complexity of the connector.
In this flat panel display device, a recess is formed in the attaching surface of the supporting member, and the connector is disposed in the recess. Specially, the recess is formed in the thick part of the supporting member and the connector is supported by a supporting surface such as a bottom face of the recess. Therefore, the connector is supported by the supporting surface of the supporting member from the backside in a contacting direction thereby determining the relative position between the supporting member and the connector and thus achieving improved reliability associated with the electrical connection. Further, the support member is joined to the other member such as circuit board by an engaging element supporting member formed on the supporting member. Due to the elasticity of the connector, supporting member the connector is urged into contact with the other member thereby electrically connecting the connector and the other member to each other.
In this aspect of the present invention, the supporting member is attached to another member disposed in an electronic device such that the connector is urged into contact with the other member thereby electrically connecting them to each other. It becomes unnecessary to separately perform the process of attaching the supporting member to the other member and the process of electrically connecting the connector to the corresponding connector. As a result, the process of attaching and electrically connecting the liquid crystal display device process becomes very easy. Furthermore, automation of the process of attaching and electrically connecting the liquid crystal display device can be achieved very easily. Herein, the connector may include a terminal part consisting of a plurality of terminals (for example, an interconnection terminal part consisting of interconnection terminals formed on an interconnection substrate). In this case, a corresponding terminal part consisting of a plurality of terminals corresponding to the respective terminals of the connector is formed on the corresponding connector (for example, a connection terminal part consisting of a plurality of connection terminals is formed on a circuit board by means of a patterning technique).
According to the another aspect of the present invention, a asupporting member is arranged behind a display panel which has a flat shape. A flat shaped panel such as liquid crystal panel is employed as a display panel, and a backlight which has a light guiding member is sometimes used as the supporting member. Behind the supporting member, another member such as a circuit board is positioned so as to hold the supporting member between the display panel and the circuit board. The other member such as circuit board is attached to an attaching surface of the supporting member, which is a surface of an opposite the side where the liquid crystal panel is supported.
In the supporting member, an opening is provided and a connector which has an elastic characteristic is inserted into the opening. The liquid crystal display and the circuit board are electrically connected to each other via the connector. For electrical connection of the circuit board and the liquid crystal panel, terminals (panel terminals) are formed on a surface of the, liquid crystal panel, and other terminals are formed on the circuit board. The terminals of the liquid crystal panel and these of the circuit board face each other via connector. To achieve the electrical connection between the electrodes (connection terminals) of the circuit board and the electrodes of the liquid crystal panel, a rubber connector that comprises an insulating elastic material and conductive members disposed in the insulating material is preferably used. Sometimes, a rubber connector comprises an insulating elastic material and a plurality of metal wires wound around the insulating material is used.
In this connector, ones of the terminals of the liquid crystal panel and respective ones of the terminals of the circuit board are connected by the respective conductive member. Pressure is applied to the insulating elastic material into contact with the other member thereby achieving electric connection between the terminals of the liquid crystal panel and those of the other member. In this aspect, the conductive members of the connector are electrically connected to the terminal of the liquid crystal panel in a direct fashion so that it becomes unnecessary to extend an interconnection member along a long path, and thus it becomes possible to reduce the total size of the liquid crystal display device.
In this aspect, an opening is formed in the supporting member, and the connector is disposed between the liquid crystal panel and the circuit board and is attached with an extended part of the liquid crystal panel, in which terminals are formed. Further, in this aspect, a pressing part is provided for supporting the liquid crystal panel by pressing the liquid crystal panel in the contacting direction of the connector toward the circuit board. The pressing part comprises, for example, a part of an outer frame of the liquid crystal panel, which is positioned so as to press the connector from the opposite side thereof so that the deforming stress applied to the liquid crystal panel is further reduced thereby ensuring that the liquid crystal panel is prevented from being damaged.
The liquid crystal display device according to any mode of the present lo invention may be attached to various types of electronic devices. In particular, the liquid crystal display device according to the invention may be advantageously attached in a direct fashion to a circuit board in an electronic device.